Abstract: OBJECTIVE To establish the HPLC fingerprints of flavonoid from Citrus changshan-huyou Y. B. peels, and related analysis between antioxidant activities and HPLC fingerprint. METHODS The fingerprint of flavonoids in Citrus changshan-huyou Y. B. peels was established by HPLC. Antioxidant activeties of the extracts were evaluated in vitro according to DPPH assay. Then the correlation was surveyed between the components in HPLC fingerprint and antioxidant activities by the multiple linear regression analysis. RESULTS The extract exhibited significant antioxidant activeties in vitro. The DPPH free radical efficiency had a positive correlation with naringin content of the extract (P<0.01) while neohesperidin showed an approximate correlation (P<0.05). CONCLUSION Antioxidant activities may be based on naringin and neohesperidin mainly.